FortiManager
FortiManager supports network operations use cases for centralized management, best practices compliance, and workflow automation to provide better protection against breaches.
mvlasak
Staff
Staff
Article Id 398719
Description

This article explains how to convert a PKCS#12 or PFX certificate created with a newer OpenSSL version that FortiManager/FortiAnalyzer to a legacy format using OpenSSL on a Linux system. This is required when importing certain certificates into FortiManager/FortiAnalyzer if the newer format is not supported. 

Scope FortiManager/FortiGate v7.x.
Solution

When importing a local certificate under System Settings -> Certificates does not work because the certificate was created with a newer OpenSSL version that FortiManager/FortiAnalyzer does not yet support.

 

Importing certificate Error will be something like 'Importing local certificate failed. It might already exist'.

 

Here is a step-by-step procedure on a Linux PC using Linux commands to convert and export the certificate so it can be successfully uploaded to FortiManager/FortiAnalyzer.

 

ubuntu@ubuntu1910:~/Documents$ mkdir legacy_folder

 

ubuntu@buntu1910:~/Documents$ openssl pkcs12 -in <CERTIFICATE_NAME>.pfx -out legacy_folder/key.pem -nocerts -nodes -legacy
Enter Import Password:

 

ubuntu@ubuntu1910:~/Documents$ openssl pkcs12 -in <CERTIFICATE_NAME>.pfx -out legacy_folder/cert.pem -nokeys -nodes -legacy
Enter Import Password: xxxxxx

 

ubuntu@ubuntu1910:~/Documents$ openssl rsa -in legacy_folder/key.pem -out key_legacy_new.pem
writing RSA key

 

ubuntu@ubuntu1910:~/Documents$ openssl pkcs12 -export -out legacy_version.pfx -inkey key_legacy_new.pem -in legacy_folder/cert.pem
Enter Export Password: xxxxxx
Verifying - Enter Export Password: xxxxxx

Once the certificate is converted to the legacy format, it can then be uploaded to FortiManager/FortiAnalyzer under System Settings -> Certificates -> Create New/Import.


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Note: 

When a user receives a certificate in .cer format along with a private key protected by a password, it is necessary to convert it to a .pfx file.

 

To create a .pfx file (also known as a .p12 file) from a .cer (certificate) file and a private key, OpenSSL can be used. This command combines the certificate and its corresponding private key into a single, password-protected file — often required for server deployments or for importing into other systems.

 

Example command:
$ openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.cer

[Enter Export Password: xxxxxxx
Verifying - Enter Export Password: xxxxxx

 

Explanation of the command:

  • openssl pkcs12: Uses the OpenSSL tool to handle PKCS#12 format files (.pfx/.p12).
  • -export: Tells OpenSSL to export the certificate and private key into a new .pfx file.
  • -out certificate.pfx: Specifies the name and location of the output .pfx file (for example, certificate.pfx).
  • -inkey privateKey.key: Specifies the path to the private key file (for example, privateKey.key).
  • -in certificate.cer: Specifies the path to the certificate file (for example, certificate.cer).